Wireless Power Transfer System For Listening Devices

ABSTRACT

A wireless power transfer system is provided for mobile charging of one or more listening devices having wireless power receiving antennas couplable to a wireless power transfer antenna. The system includes a case configured for attachment to a mobile electronic device having a wireless power transfer antenna. The case includes a hollow for each of the listening devices, with each hollow being shaped and located to hold a respective listening device in a coupling position with the wireless power transfer antenna of the mobile electronic device when the case is mounted to the mobile electronic device. An attachment may be used to mount the case to the mobile electronic device.

TECHNICAL FIELD

The present disclosure generally relates to systems and methods forwireless transfer of electrical power and/or electrical data signals,and, more particularly, to systems and methods for efficiently chargingand recharging a mobile device accessory.

BACKGROUND

Wireless connection systems are used in a variety of applications forthe wireless transfer of electrical energy, electrical power,electromagnetic energy, electrical data signals, among other knownwirelessly transmittable signals. Such systems often use inductivewireless power transfer, which occurs when magnetic fields created by atransmitting element induce an electric field, and hence, an electriccurrent, in a receiving element. These transmitting and receivingelements will often take the form of coiled wires and/or antennas.

Transmission of one or more of electrical energy, electrical power,electromagnetic energy and/or electronic data signals from one suchcoiled antenna to another, generally, operates at an operating frequencyand/or an operating frequency range. The operating frequency may beselected for a variety of reasons, such as, but not limited to, powertransfer characteristics, power level characteristics, self-resonantfrequency restraints, design requirements, adherence to standards bodyrequirements (e.g. electromagnetic interference (EMI) requirements,specific absorption rate (SAR) requirements, among other things), billof materials (BOM) limitations, and/or form factor constraints, amongother things. It is to be noted that, “self-resonating frequency,” asknown to those having skill in the art, generally refers to the resonantfrequency of a passive component (e.g., an inductor) due to theparasitic characteristics of the component.

When such systems operate to wirelessly transfer power from atransmission system to a receiver system, via the coils and/or antennas,it is often desired to simultaneously or intermittently communicateelectronic data from one system to the other. The efficient transfer ofpower and data may be affected by the location and stability of one orboth of the sending and receiving antennas.

SUMMARY

To that end, a passive mechanical attachment is provided for a mobilephone or other portable device that when attached to the phone, alignsthe receiver coils in a peripheral device with an NFC coil of the mobilephone or other portable device. By way of example, the system may beutilized for earbuds as a replacement for a charging case, thus loweringcosts significantly for earbud manufacturers, while also providing anattractive means to pack true wireless earbuds with a mobile device.

The system may be used for multiple devices to be charged, e.g., tocharge two earbuds on a mobile phone, or for a single one, e.g., tocharge one earbud on a wrist wearable device. The passive mechanicalattachment may be made of an economical and efficient material such asplastic and will add little to the overall cost of a mobile device.Attachment of the system to the mobile device may be effected viamechanical connection, e.g., via one or more indents in the attachmentso that it slides onto a specific phone. Alternatively, mechanicalconnection may be effected via an adjustable clip styleexpander/retractor to fit onto a plurality of phone sizes and such thatit can be moved up or down to charge device(s).

In accordance with one aspect of the disclosure, a wireless powertransfer system for mobile charging of one or more listening devicesincludes a case configured for attachment to a mobile electronic devicehaving a wireless power transfer antenna. In this aspect, the caseincludes a hollow for each of the listening devices, and each suchdevice has a wireless power receiving antenna couplable to a wirelesspower transfer antenna. Each hollow is shaped and located to hold alistening device in a coupling position with the wireless power transferantenna of the mobile electronic device when the case is mounted to themobile electronic device. An attachment is used to mount the case to themobile electronic device.

In a refinement, the wireless power receiving antenna couples at anoperating frequency in a range of about 13.553 MHz to about 13.567 MHz.In a further refinement, the output power of the wireless power transferantenna is greater than about 1 Watt. In a further refinement, there aretwo listening devices and the case includes two respective hollows. Thecase may be further configured for attachment to a back surface of themobile electronic device.

In a refinement, the mobile electronic device is a mobile phone, and inanother refinement, the mobile electronic device is a wearable device.The attachment may include at least one of a clip, a bracket, anadhesive and a hook and loop fastener.

In accordance with another aspect of the disclosure, a Near-FieldCommunications Direct Charge (NFC-DC) system is provided for mobilecharging of one or more listening devices. The system includes a caseconfigured for attachment to a mobile electronic device having a NFC-DCpower transfer antenna. The case includes a hollow for each listeningdevice, and each such device includes a NFC-DC receiving antennacouplable to a NFC-DC power transfer antenna, wherein each hollow isshaped and located to hold a listening device in a coupling positionwith the NFC-DC power transfer antenna of the mobile electronic devicewhen the case is mounted to the mobile electronic device. An attachmentis used for attaching the case to the mobile electronic device.

In a refinement, the NFC-DC receiving antenna couples at an operatingfrequency in a range of about 13.553 MHz to about 13.567 MHz and inanother refinement, the output power of the NFC-DC power transferantenna is greater than about 1 Watt. In yet a further refinement, theone or more listening devices include two listening devices and the caseincludes two respective hollows.

In a refinement, the case is configured for attachment to a back surfaceof the mobile electronic device, and in accordance with additionalrefinements, the mobile electronic device is one of a mobile phone and awearable device. In yet another refinement, the attachment comprises atleast one of a clip, a bracket, an adhesive and a hook and loopfastener.

In accordance with another aspect of the disclosure, a wireless powertransfer system is provided including a mobile electronic device and acase attached to the mobile electronic device. The mobile electronicdevice includes a wireless power transfer antenna associated with awireless power transmission system, and the case, attached to the mobileelectronic device adjacent the wireless power transfer antenna, includesa hollow for each of one or more listening devices, each such devicehaving a wireless power receiving antenna couplable to the wirelesspower transfer antenna. Each hollow is shaped and located to hold itslistening device in a coupling position with the wireless power transferantenna of the mobile electronic device.

In a refinement, the wireless power receiving antenna and wireless powertransfer antenna couple at an operating frequency in a range of about13.553 MHz to about 13.567 MHz, and in a further refinement, the outputpower of the wireless power transfer antenna is greater than about 1Watt. The mobile electronic device may be a mobile phone or a wearabledevice.

These and other aspects and features of the present disclosure will bebetter understood when read in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an embodiment of a system for wirelesslytransferring one or more of electrical energy, electrical power signals,electrical power, electromagnetic energy, electronic data, andcombinations thereof, in accordance with the present disclosure.

FIG. 2 is a block diagram illustrating components of a wirelesstransmission system of the system of FIG. 1 and a wireless receiversystem of the system of FIG. 1 , in accordance with FIG. 1 and thepresent disclosure.

FIG. 3 is a block diagram illustrating components of a transmissioncontrol system of the wireless transmission system of FIG. 2 , inaccordance with FIG. 1 , FIG. 2 , and the present disclosure.

FIG. 4 is a block diagram illustrating components of a sensing system ofthe transmission control system of FIG. 3 , in accordance with FIGS. 1-3and the present disclosure.

FIG. 5 is a block diagram illustrating components of a powerconditioning system of the wireless transmission system of FIG. 2 , inaccordance with FIG. 1 , FIG. 2 , and the present disclosure.

FIG. 6 is a block diagram of elements of the wireless transmissionsystem of FIGS. 1-5 , further illustrating components of an amplifier ofthe power conditioning system of FIG. 5 and signal characteristics forwireless power transmission, in accordance with FIGS. 1-5 and thepresent disclosure.

FIG. 7 is an electrical schematic diagram of elements of the wirelesstransmission system of FIGS. 1-6 , further illustrating components of anamplifier of the power conditioning system of FIGS. 5-6 , in accordancewith FIGS. 1-6 and the present disclosure.

FIG. 8 is an exemplary plot illustrating rise and fall of “on” and “off”conditions when a signal has in-band communications via on-off keying.

FIG. 9 is a block diagram illustrating components of a receiver controlsystem and a receiver power conditioning system of the wireless receiversystem of FIG. 2 , in accordance with FIG. 1 , FIG. 2 , and the presentdisclosure.

FIG. 10 is a block diagram of elements of the wireless receiver systemof FIGS. 1-2 and 9 , further illustrating components of an amplifier ofthe power conditioning system of FIG. 9 and signal characteristics forwireless power transmission, in accordance with FIGS. 1-2, 9 , and thepresent disclosure.

FIG. 11 is an electrical schematic diagram of elements of the wirelessreceiver system of FIGS. 1-2 and 9-10 , further illustrating componentsof an amplifier of the power conditioning system of FIGS. 9-10 , inaccordance with FIGS. 1-2, 9-10 and the present disclosure.

FIG. 12 is a top view of a non-limiting, exemplary antenna, for use asone or both of a transmission antenna and a receiver antenna of thesystem of FIGS. 1-7, 9-11 and/or any other systems, methods, orapparatus disclosed herein, in accordance with the present disclosure.

FIG. 13 is a side view, with cross-sectional denotations, of exemplaryearbuds and an associated charging case, within which the wireless powertransfer systems disclosed herein may be implemented for wireless powertransmission from the charging case to the earbuds, in accordance withFIGS. 1-7, 9-12 , and the present disclosure.

FIG. 14 is a simplified back view of a mobile phone whereon a listeningdevice case has been mounted in accordance with the present disclosure.

FIG. 15 is a simplified side cross-sectional view of a mobile phonewhereon a listening device case has been mounted in accordance with thepresent disclosure.

FIG. 16 is a simplified rear perspective view of a listening device casein accordance with the present disclosure.

FIG. 17 is a simplified rear perspective view of an alternativelistening device case in accordance with the present disclosure.

FIG. 18 is a simplified rear perspective view of yet another alternativelistening device case in accordance with the present disclosure.

FIG. 19 is a simplified side cross-sectional view of a mobile phonewhereon a listening device case has been mounted, the case having analignment ledge, in accordance with the present disclosure.

While the following detailed description will be given with respect tocertain illustrative embodiments, it should be understood that thedrawings are not necessarily to scale and the disclosed embodiments aresometimes illustrated diagrammatically and in partial views. Inaddition, in certain instances, details which are not necessary for anunderstanding of the disclosed subject matter or which render otherdetails too difficult to perceive may have been omitted. It shouldtherefore be understood that this disclosure is not limited to theparticular embodiments disclosed and illustrated herein, but rather to afair reading of the entire disclosure and claims, as well as anyequivalents thereto. Additional, different, or fewer components andmethods may be included in the systems and methods.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth byway of examples in order to provide a thorough understanding of therelevant teachings. However, it should be apparent to those skilled inthe art that the present teachings may be practiced without suchdetails. In other instances, well known methods, procedures, components,and/or circuitry have been described at a relatively high-level, withoutdetail, in order to avoid unnecessarily obscuring aspects of the presentteachings.

Turning more specifically to the challenge at hand, NFC charging from aphone to a peripheral (e.g., earbuds, wrist wearables, etc.) is desiredin next generation mobile devices (e.g., cellular phones). However, asnoted above, the efficient wireless transfer of power and data may beaffected by the location and stability of one or both of the sending andreceiving antennas. Moreover, when a peripheral is being wirelesslycharged by a portable device such as a mobile phone, it may beinconvenient for the user to assure alignment of the charged andcharging devices. For example, it would be inconvenient for a user toleave their phone face down, if the charging coil is on the back, inorder to maintain one or more earbuds or other peripheral devicesaligned and located for charging and data exchange with the phone.

Referring now to the drawings and with specific reference to FIG. 1 , awireless power transfer system 10 is illustrated. The wireless powertransfer system 10 provides for the wireless transmission of electricalsignals, such as, but not limited to, electrical energy, electricalpower, electrical power signals, electromagnetic energy, andelectronically transmittable data (“electronic data”). As used herein,the term “electrical power signal” refers to an electrical signaltransmitted specifically to provide meaningful electrical energy forcharging and/or directly powering a load, whereas the term “electronicdata signal” refers to an electrical signal that is utilized to conveydata across a medium.

The wireless power transfer system 10 provides for the wirelesstransmission of electrical signals via near field magnetic coupling. Asshown in the embodiment of FIG. 1 , the wireless power transfer system10 includes a wireless transmission system 20 and a wireless receiversystem 30. The wireless receiver system is configured to receiveelectrical signals from, at least, the wireless transmission system 20.In some examples, such as examples wherein the wireless power transfersystem is configured for wireless power transfer via the Near FieldCommunications Direct Charge (NFC-DC) or Near Field CommunicationsWireless Charging (NFC WC) draft or accepted standard, the wirelesstransmission system 20 may be referenced as a “listener” of the NFC-DCwireless transfer system 20 and the wireless receiver system 30 may bereferenced as a “poller” of the NFC-DC wireless transfer system.

As illustrated, the wireless transmission system 20 and wirelessreceiver system 30 may be configured to transmit electrical signalsacross, at least, a separation distance or gap 17. A separation distanceor gap, such as the gap 17, in the context of a wireless power transfersystem, such as the system 10, does not include a physical connection,such as a wired connection. There may be intermediary objects located ina separation distance or gap, such as, but not limited to, air, acounter top, a casing for an electronic device, a plastic filament, aninsulator, a mechanical wall, among other things; however, there is nophysical, electrical connection at such a separation distance or gap.

Thus, the combination of the wireless transmission system 20 and thewireless receiver system 30 create an electrical connection without theneed for a physical connection. As used herein, the term “electricalconnection” refers to any facilitation of a transfer of an electricalcurrent, voltage, and/or power from a first location, device, component,and/or source to a second location, device, component, and/ordestination. An “electrical connection” may be a physical connection,such as, but not limited to, a wire, a trace, a via, among otherphysical electrical connections, connecting a first location, device,component, and/or source to a second location, device, component, and/ordestination. Additionally or alternatively, an “electrical connection”may be a wireless power and/or data transfer, such as, but not limitedto, magnetic, electromagnetic, resonant, and/or inductive field, amongother wireless power and/or data transfers, connecting a first location,device, component, and/or source to a second location, device,component, and/or destination.

In some cases, the gap 17 may also be referenced as a “Z-Distance,”because, if one considers an antenna 21, 31 each to be disposedsubstantially along respective common X-Y planes, then the distanceseparating the antennas 21, 31 is the gap in a “Z” or “depth” direction.However, flexible and/or non-planar coils are certainly contemplated byembodiments of the present disclosure and, thus, it is contemplated thatthe gap 17 may not be uniform, across an envelope of connectiondistances between the antennas 21, 31. It is contemplated that varioustunings, configurations, and/or other parameters may alter the possiblemaximum distance of the gap 17, such that electrical transmission fromthe wireless transmission system 20 to the wireless receiver system 30remains possible.

The wireless power transfer system 10 operates when the wirelesstransmission system 20 and the wireless receiver system 30 are coupled.As used herein, the terms “couples,” “coupled,” and “coupling” generallyrefer to magnetic field coupling, which occurs when a transmitter and/orany components thereof and a receiver and/or any components thereof arecoupled to each other through a magnetic field. Such coupling mayinclude coupling, represented by a coupling coefficient (k), that is atleast sufficient for an induced electrical power signal, from atransmitter, to be harnessed by a receiver. Coupling of the wirelesstransmission system 20 and the wireless receiver system 30, in thesystem 10, may be represented by a resonant coupling coefficient of thesystem 10 and, for the purposes of wireless power transfer, the couplingcoefficient for the system 10 may be in the range of about 0.01 and 0.9.

As illustrated, the wireless transmission system 20 may be associatedwith a host device 11, which may receive power from an input powersource 12. The host device 11 may be any electrically operated device,circuit board, electronic assembly, dedicated charging device, or anyother contemplated electronic device. Example host devices 11, withwhich the wireless transmission system 20 may be associated therewith,include, but are not limited to including, a device that includes anintegrated circuit, cases for wearable electronic devices, receptaclesfor electronic devices, a portable computing device, clothing configuredwith electronics, storage medium for electronic devices, chargingapparatus for one or multiple electronic devices, dedicated electricalcharging devices, activity or sport related equipment, goods, and/ordata collection devices, among other contemplated electronic devices.

As illustrated, one or both of the wireless transmission system 20 andthe host device 11 are operatively associated with an input power source12. The input power source 12 may be or may include one or moreelectrical storage devices, such as an electrochemical cell, a batterypack, and/or a capacitor, among other storage devices. Additionally oralternatively, the input power source 12 may be any electrical inputsource (e.g., any alternating current (AC) or direct current (DC)delivery port) and may include connection apparatus from said electricalinput source to the wireless transmission system 20 (e.g., transformers,regulators, conductive conduits, traces, wires, or equipment, goods,computer, camera, mobile phone, and/or other electrical deviceconnection ports and/or adaptors, such as but not limited to USB portsand/or adaptors, among other contemplated electrical components).

Electrical energy received by the wireless transmission system 20 isthen used for at least two purposes: to provide electrical power tointernal components of the wireless transmission system 20 and toprovide electrical power to the transmitter antenna 21. The transmitterantenna 21 is configured to wirelessly transmit the electrical signalsconditioned and modified for wireless transmission by the wirelesstransmission system 20 via near-field magnetic coupling (NFMC).Near-field magnetic coupling enables the transfer of signals wirelesslythrough magnetic induction between the transmitter antenna 21 and areceiving antenna 31 of, or associated with, the wireless receiversystem 30. Near-field magnetic coupling may be and/or be referred to as“inductive coupling,” which, as used herein, is a wireless powertransmission technique that utilizes an alternating electromagneticfield to transfer electrical energy between two antennas. Such inductivecoupling is the near field wireless transmission of magnetic energybetween two magnetically coupled coils that are tuned to resonate at asimilar frequency. Accordingly, such near-field magnetic coupling mayenable efficient wireless power transmission via resonant transmissionof confined magnetic fields. Further, such near-field magnetic couplingmay provide connection via “mutual inductance,” which, as defined hereinis the production of an electromotive force in a circuit by a change incurrent in a second circuit magnetically coupled to the first.

In one or more embodiments, the inductor coils of either the transmitterantenna 21 or the receiver antenna 31 are strategically positioned tofacilitate reception and/or transmission of wirelessly transferredelectrical signals through near field magnetic induction. Antennaoperating frequencies may comprise relatively high operating frequencyranges, examples of which may include, but are not limited to, 6.78 MHz(e.g., in accordance with the Rezence and/or Airfuel interface standardand/or any other proprietary interface standard operating at a frequencyof 6.78 MHz), 13.56 MHz (e.g., in accordance with the NFC standard,defined by ISO/IEC standard 18092), 27 MHz, and/or an operatingfrequency of another proprietary operating mode. The operatingfrequencies of the antennas 21, 31 may be operating frequenciesdesignated by the International Telecommunications Union (ITU) in theIndustrial, Scientific, and Medical (ISM) frequency bands, including notlimited to 6.78 MHz, 13.56 MHz, and 27 MHz, which are designated for usein wireless power transfer. In systems wherein the wireless powertransfer system 10 is operating within the NFC-DC standards and/or draftstandards, the operating frequency may be in a range of about 13.553 MHzto about 13.567 MHz.

The transmitting antenna and the receiving antenna of the presentdisclosure may be configured to transmit and/or receive electrical powerhaving a magnitude that ranges from about 10 milliwatts (mW) to about500 watts (W). In one or more embodiments the inductor coil of thetransmitting antenna 21 is configured to resonate at a transmittingantenna resonant frequency or within a transmitting antenna resonantfrequency band.

As known to those skilled in the art, a “resonant frequency” or“resonant frequency band” refers a frequency or frequencies whereinamplitude response of the antenna is at a relative maximum, or,additionally or alternatively, the frequency or frequency band where thecapacitive reactance has a magnitude substantially similar to themagnitude of the inductive reactance. In one or more embodiments, thetransmitting antenna resonant frequency is at a high frequency, as knownto those in the art of wireless power transfer.

The wireless receiver system 30 may be associated with at least oneelectronic device 14, wherein the electronic device 14 may be any devicethat requires electrical power for any function and/or for power storage(e.g., via a battery and/or capacitor). Additionally, the electronicdevice 14 may be any device capable of receipt of electronicallytransmissible data. For example, the device may be, but is not limitedto being, a handheld computing device, a mobile device, a portableappliance, an integrated circuit, an identifiable tag, a kitchen utilitydevice, an electronic tool, an electric vehicle, a game console, arobotic device, a wearable electronic device (e.g., an electronic watch,electronically modified glasses, altered-reality (AR) glasses, virtualreality (VR) glasses, among other things), a portable scanning device, aportable identifying device, a sporting good, an embedded sensor, anInternet of Things (IoT) sensor, IoT enabled clothing, IoT enabledrecreational equipment, industrial equipment, medical equipment, amedical device a tablet computing device, a portable control device, aremote controller for an electronic device, a gaming controller, amongother things.

For the purposes of illustrating the features and characteristics of thedisclosed embodiments, arrow-ended lines are utilized to illustratetransferrable and/or communicative signals and various patterns are usedto illustrate electrical signals that are intended for powertransmission and electrical signals that are intended for thetransmission of data and/or control instructions. Solid lines indicatesignal transmission of electrical energy over a physical and/or wirelesspower transfer, in the form of power signals that are, ultimately,utilized in wireless power transmission from the wireless transmissionsystem 20 to the wireless receiver system 30. Further, dotted lines areutilized to illustrate electronically transmittable data signals, whichultimately may be wirelessly transmitted from the wireless transmissionsystem 20 to the wireless receiver system 30.

While the systems and methods herein illustrate the transmission ofwirelessly transmitted energy, wireless power signals, wirelesslytransmitted power, wirelessly transmitted electromagnetic energy, and/orelectronically transmittable data, it is certainly contemplated that thesystems, methods, and apparatus disclosed herein may be utilized in thetransmission of only one signal, various combinations of two signals, ormore than two signals and, further, it is contemplated that the systems,method, and apparatus disclosed herein may be utilized for wirelesstransmission of other electrical signals in addition to or uniquely incombination with one or more of the above mentioned signals. In someexamples, the signal paths of solid or dotted lines may represent afunctional signal path, whereas, in practical application, the actualsignal is routed through additional components en route to its indicateddestination. For example, it may be indicated that a data signal routesfrom a communications apparatus to another communications apparatus;however, in practical application, the data signal may be routed throughan amplifier, then through a transmission antenna, to a receiverantenna, where, on the receiver end, the data signal is decoded by arespective communications device of the receiver.

Turning now to FIG. 2 , the wireless connection system 10 is illustratedas a block diagram including example sub-systems of both the wirelesstransmission system 20 and the wireless receiver system 30. The wirelesstransmission system 20 may include, at least, a power conditioningsystem 40, a transmission control system 26, a transmission tuningsystem 24, and the transmission antenna 21. A first portion of theelectrical energy input from the input power source 12 is configured toelectrically power components of the wireless transmission system 20such as, but not limited to, the transmission control system 26. Asecond portion of the electrical energy input from the input powersource 12 is conditioned and/or modified for wireless powertransmission, to the wireless receiver system 30, via the transmissionantenna 21. Accordingly, the second portion of the input energy ismodified and/or conditioned by the power conditioning system 40. Whilenot illustrated, it is certainly contemplated that one or both of thefirst and second portions of the input electrical energy may bemodified, conditioned, altered, and/or otherwise changed prior toreceipt by the power conditioning system 40 and/or transmission controlsystem 26, by further contemplated subsystems (e.g., a voltageregulator, a current regulator, switching systems, fault systems, safetyregulators, among other things).

Referring now to FIG. 3 , with continued reference to FIGS. 1 and 2 ,subcomponents and/or systems of the transmission control system 26 areillustrated. The transmission control system 26 may include a sensingsystem 50, a transmission controller 28, a communications system 29, adriver 48, and a memory 27.

The transmission controller 28 may be any electronic controller orcomputing system that includes, at least, a processor which performsoperations, executes control algorithms, stores data, retrieves data,gathers data, controls and/or provides communication with othercomponents and/or subsystems associated with the wireless transmissionsystem 20, and/or performs any other computing or controlling taskdesired. The transmission controller 28 may be a single controller ormay include more than one controller disposed to control variousfunctions and/or features of the wireless transmission system 20.Functionality of the transmission controller 28 may be implemented inhardware and/or software and may rely on one or more data maps relatingto the operation of the wireless transmission system 20. To that end,the transmission controller 28 may be operatively associated with thememory 27. The memory may include one or more of internal memory,external memory, and/or remote memory (e.g., a database and/or serveroperatively connected to the transmission controller 28 via a network,such as, but not limited to, the Internet). The internal memory and/orexternal memory may include, but are not limited to including, one ormore of a read only memory (ROM), including programmable read-onlymemory (PROM), erasable programmable read-only memory (EPROM orsometimes but rarely labelled EROM), electrically erasable programmableread-only memory (EEPROM), random access memory (RAM), including dynamicRAM (DRAM), static RAM (SRAM), synchronous dynamic RAM (SDRAM), singledata rate synchronous dynamic RAM (SDR SDRAM), double data ratesynchronous dynamic RAM (DDR SDRAM, DDR2, DDR3, DDR4), and graphicsdouble data rate synchronous dynamic RAM (GDDR SDRAM, GDDR2, GDDR3,GDDR4, GDDR5, a flash memory, a portable memory, and the like. Suchmemory media are examples of nontransitory machine readable and/orcomputer readable memory media.

While particular elements of the transmission control system 26 areillustrated as independent components and/or circuits (e.g., the driver48, the memory 27, the communications system 29, the sensing system 50,among other contemplated elements) of the transmission control system26, such components may be integrated with the transmission controller28. In some examples, the transmission controller 28 may be anintegrated circuit configured to include functional elements of one orboth of the transmission controller 28 and the wireless transmissionsystem 20, generally.

As illustrated, the transmission controller 28 is in operativeassociation, for the purposes of data transmission, receipt, and/orcommunication, with, at least, the memory 27, the communications system29, the power conditioning system 40, the driver 48, and the sensingsystem 50. The driver 48 may be implemented to control, at least inpart, the operation of the power conditioning system 40. In someexamples, the driver 48 may receive instructions from the transmissioncontroller 28 to generate and/or output a generated pulse widthmodulation (PWM) signal to the power conditioning system 40. In somesuch examples, the PWM signal may be configured to drive the powerconditioning system 40 to output electrical power as an alternatingcurrent signal, having an operating frequency defined by the PWM signal.In some examples, PWM signal may be configured to generate a duty cyclefor the AC power signal output by the power conditioning system 40. Insome such examples, the duty cycle may be configured to be about 50% ofa given period of the AC power signal.

The sensing system may include one or more sensors, wherein each sensormay be operatively associated with one or more components of thewireless transmission system 20 and configured to provide informationand/or data. The term “sensor” is used in its broadest interpretation todefine one or more components operatively associated with the wirelesstransmission system 20 that operate to sense functions, conditions,electrical characteristics, operations, and/or operating characteristicsof one or more of the wireless transmission system 20, the wirelessreceiving system 30, the input power source 12, the host device 11, thetransmission antenna 21, the receiver antenna 31, along with any othercomponents and/or subcomponents thereof.

As illustrated in the embodiment of FIG. 4 , the sensing system 50 mayinclude, but is not limited to including, a thermal sensing system 52,an object sensing system 54, a receiver sensing system 56, and/or anyother sensor(s) 58. Within these systems, there may exist even morespecific optional additional or alternative sensing systems addressingparticular sensing aspects required by an application, such as, but notlimited to: a condition-based maintenance sensing system, a performanceoptimization sensing system, a state-of-charge sensing system, atemperature management sensing system, a component heating sensingsystem, an IoT sensing system, an energy and/or power management sensingsystem, an impact detection sensing system, an electrical status sensingsystem, a speed detection sensing system, a device health sensingsystem, among others. The object sensing system 54, may be a foreignobject detection (FOD) system.

Each of the thermal sensing system 52, the object sensing system 54, thereceiver sensing system 56 and/or the other sensor(s) 58, including theoptional additional or alternative systems, are operatively and/orcommunicatively connected to the transmission controller 28. The thermalsensing system 52 is configured to monitor ambient and/or componenttemperatures within the wireless transmission system 20 or otherelements nearby the wireless transmission system 20. The thermal sensingsystem 52 may be configured to detect a temperature within the wirelesstransmission system 20 and, if the detected temperature exceeds athreshold temperature, the transmission controller 28 prevents thewireless transmission system 20 from operating. Such a thresholdtemperature may be configured for safety considerations, operationalconsiderations, efficiency considerations, and/or any combinationsthereof. In a non-limiting example, if, via input from the thermalsensing system 52, the transmission controller 28 determines that thetemperature within the wireless transmission system 20 has increasedfrom an acceptable operating temperature to an undesired operatingtemperature (e.g., in a non-limiting example, the internal temperatureincreasing from about 20 ° Celsius (C) to about 50° C., the transmissioncontroller 28 prevents the operation of the wireless transmission system20 and/or reduces levels of power output from the wireless transmissionsystem 20. In some non-limiting examples, the thermal sensing system 52may include one or more of a thermocouple, a thermistor, a negativetemperature coefficient (NTC) resistor, a resistance temperaturedetector (RTD), and/or any combinations thereof.

As depicted in FIG. 4 , the transmission sensing system 50 may includethe object sensing system 54. The object sensing system 54 may beconfigured to detect one or more of the wireless receiver system 30and/or the receiver antenna 31, thus indicating to the transmissioncontroller 28 that the receiver system 30 is proximate to the wirelesstransmission system 20. Additionally or alternatively, the objectsensing system 54 may be configured to detect presence of unwantedobjects in contact with or proximate to the wireless transmission system20. In some examples, the object sensing system 54 is configured todetect the presence of an undesired object. In some such examples, ifthe transmission controller 28, via information provided by the objectsensing system 54, detects the presence of an undesired object, then thetransmission controller 28 prevents or otherwise modifies operation ofthe wireless transmission system 20. In some examples, the objectsensing system 54 utilizes an impedance change detection scheme, inwhich the transmission controller 28 analyzes a change in electricalimpedance observed by the transmission antenna 20 against a known,acceptable electrical impedance value or range of electrical impedancevalues.

Additionally or alternatively, the object sensing system 54 may utilizea quality factor (Q) change detection scheme, in which the transmissioncontroller 28 analyzes a change from a known quality factor value orrange of quality factor values of the object being detected, such as thereceiver antenna 31. The “quality factor” or “Q” of an inductor can bedefined as (frequency (Hz)×inductance (H))/resistance (ohms), wherefrequency is the operational frequency of the circuit, inductance is theinductance output of the inductor and resistance is the combination ofthe radiative and reactive resistances that are internal to theinductor. “Quality factor,” as defined herein, is generally accepted asan index (figure of measure) that measures the efficiency of anapparatus like an antenna, a circuit, or a resonator. In some examples,the object sensing system 54 may include one or more of an opticalsensor, an electro-optical sensor, a Hall effect sensor, a proximitysensor, and/or any combinations thereof.

The receiver sensing system 56 is any sensor, circuit, and/orcombinations thereof configured to detect presence of any wirelessreceiving system that may be couplable with the wireless transmissionsystem 20. In some examples, the receiver sensing system 56 and theobject sensing system 54 may be combined, may share components, and/ormay be embodied by one or more common components. In some examples, ifthe presence of any such wireless receiving system is detected, wirelesstransmission of electrical energy, electrical power, electromagneticenergy, and/or data by the wireless transmission system 20 to saidwireless receiving system is enabled. In some examples, if the presenceof a wireless receiver system is not detected, continued wirelesstransmission of electrical energy, electrical power, electromagneticenergy, and/or data is prevented from occurring. Accordingly, thereceiver sensing system 56 may include one or more sensors and/or may beoperatively associated with one or more sensors that are configured toanalyze electrical characteristics within an environment of or proximateto the wireless transmission system 20 and, based on the electricalcharacteristics, determine presence of a wireless receiver system 30.

Referring now to FIG. 5 , and with continued reference to FIGS. 1-4 , ablock diagram illustrating an embodiment of the power conditioningsystem 40 is illustrated. At the power conditioning system 40,electrical power is received, generally, as a DC power source, via theinput power source 12 itself or an intervening power converter,converting an AC source to a DC source (not shown). A voltage regulator46 receives the electrical power from the input power source 12 and isconfigured to provide electrical power for transmission by the antenna21 and provide electrical power for powering components of the wirelesstransmission system 21. Accordingly, the voltage regulator 46 isconfigured to convert the received electrical power into at least twoelectrical power signals, each at a proper voltage for operation of therespective downstream components: a first electrical power signal toelectrically power any components of the wireless transmission system 20and a second portion conditioned and modified for wireless transmissionto the wireless receiver system 30. As illustrated in FIG. 3 , such afirst portion is transmitted to, at least, the sensing system 50, thetransmission controller 28, and the communications system 29; however,the first portion is not limited to transmission to just thesecomponents and can be transmitted to any electrical components of thewireless transmission system 20.

The second portion of the electrical power is provided to an amplifier42 of the power conditioning system 40, which is configured to conditionthe electrical power for wireless transmission by the antenna 21. Theamplifier may function as an invertor, which receives an input DC powersignal from the voltage regulator 46 and generates an AC as output,based, at least in part, on PWM input from the transmission controlsystem 26. The amplifier 42 may be or include, for example, a powerstage invertor, such as a dual field effect transistor power stageinvertor or a quadruple field effect transistor power stage invertor.The use of the amplifier 42 within the power conditioning system 40 and,in turn, the wireless transmission system 20 enables wirelesstransmission of electrical signals having much greater amplitudes thanif transmitted without such an amplifier. For example, the addition ofthe amplifier 42 may enable the wireless transmission system 20 totransmit electrical energy as an electrical power signal havingelectrical power from about 10 mW to about 500 W. In some examples, theamplifier 42 may be or may include one or more class-E power amplifiers.Class-E power amplifiers are efficiently tuned switching poweramplifiers designed for use at high frequencies (e.g., frequencies fromabout 1 MHz to about 1 GHz). Generally, a class-E amplifier employs asingle-pole switching element and a tuned reactive network between theswitch and an output load (e.g., the antenna 21). Class E amplifiers mayachieve high efficiency at high frequencies by only operating theswitching element at points of zero current (e.g., on-to-off switching)or zero voltage (off to on switching). Such switching characteristicsmay minimize power lost in the switch, even when the switching time ofthe device is long compared to the frequency of operation. However, theamplifier 42 is certainly not limited to being a class-E power amplifierand may be or may include one or more of a class D amplifier, a class EFamplifier, an H invertor amplifier, and/or a push-pull invertor, amongother amplifiers that could be included as part of the amplifier 42.

Turning now to FIGS. 6 and 7 , the wireless transmission system 20 isillustrated, further detailing elements of the power conditioning system40, the amplifier 42, the tuning system 24, among other things. Theblock diagram of the wireless transmission system 20 illustrates one ormore electrical signals and the conditioning of such signals, alteringof such signals, transforming of such signals, inverting of suchsignals, amplification of such signals, and combinations thereof. InFIG. 6 , DC power signals are illustrated with heavily bolded lines,such that the lines are significantly thicker than other solid lines inFIG. 6 and other figures of the instant application, AC signals areillustrated as substantially sinusoidal wave forms with a thicknesssignificantly less bolded than that of the DC power signal bolding, anddata signals are represented as dotted lines. It is to be noted that theAC signals are not necessarily substantially sinusoidal waves and may beany AC waveform suitable for the purposes described below (e.g., a halfsine wave, a square wave, a half square wave, among other waveforms).FIG. 7 illustrates sample electrical components for elements of thewireless transmission system, and subcomponents thereof, in a simplifiedform. Note that FIG. 7 may represent one branch or sub-section of aschematic for the wireless transmission system 20 and/or components ofthe wireless transmission system 20 may be omitted from the schematicillustrated in FIG. 7 for clarity.

As illustrated in FIG. 6 and discussed above, the input power source 11provides an input direct current voltage (V_(DC)), which may have itsvoltage level altered by the voltage regulator 46, prior to conditioningat the amplifier 42. In some examples, as illustrated in FIG. 7 , theamplifier 42 may include a choke inductor L_(CHOKE), which may beutilized to block radio frequency interference in V_(DC), while allowingthe DC power signal of V_(DC) to continue towards an amplifiertransistor 48 of the amplifier 42. V_(CHOKE) may be configured as anysuitable choke inductor known in the art.

The amplifier 48 is configured to alter and/or invert V_(DC) to generatean AC wireless signal V_(AC), which, as discussed in more detail below,may be configured to carry one or both of an inbound and outbound datasignal (denoted as “Data” in FIG. 6 ). The amplifier transistor 48 maybe any switching transistor known in the art that is capable ofinverting, converting, and/or conditioning a DC power signal into an ACpower signal, such as, but not limited to, a field-effect transistor(FET), gallium nitride (GaN) FETS, bipolar junction transistor (BJT),and/or wide-bandgap (WBG) semiconductor transistor, among other knownswitching transistors. The amplifier transistor 48 is configured toreceive a driving signal (denoted as “PWM” in FIG. 6 ) from at a gate ofthe amplifier transistor 48 (denoted as “G” in FIG. 6 ) and invert theDC signal V_(DC) to generate the AC wireless signal at an operatingfrequency and/or an operating frequency band for the wireless powertransmission system 20. The driving signal may be a PWM signalconfigured for such inversion at the operating frequency and/oroperating frequency band for the wireless power transmission system 20.

The driving signal is generated and output by the transmission controlsystem 26 and/or the transmission controller 28 therein, as discussedand disclosed above. The transmission controller 26, 28 is configured toprovide the driving signal and configured to perform one or more ofencoding wireless data signals (denoted as “Data” in FIG. 6 ), decodingthe wireless data signals (denoted as “Data” in FIG. 6 ) and anycombinations thereof. In some examples, the electrical data signals maybe in band signals of the AC wireless power signal. In some suchexamples, such in-band signals may be on-off-keying (OOK) signalsin-band of the AC wireless power signals. For example, Type-Acommunications, as described in the NFC Standards, are a form of OOK,wherein the data signal is on-off-keyed in a carrier AC wireless powersignal operating at an operating frequency in a range of about 13.553MHz to about 13.567 MHz.

However, when the power, current, impedance, phase, and/or voltagelevels of an AC power signal are changed beyond the levels used incurrent and/or legacy hardware for high frequency wireless powertransfer (over about 500 mW transmitted), such legacy hardware may notbe able to properly encode and/or decode in-band data signals with therequired fidelity for communications functions. Such higher power in anAC output power signal may cause signal degradation due to increasingrise times for an OOK rise, increasing fall time for an OOK fall,overshooting the required voltage in an OOK rise, and/or undershootingthe voltage in an OOK fall, among other potential degradations to thesignal due to legacy hardware being ill equipped for higher power, highfrequency wireless power transfer. Thus, there is a need for theamplifier 42 to be designed in a way that limits and/or substantiallyremoves rise and fall times, overshoots, undershoots, and/or othersignal deficiencies from an in-band data signal during wireless powertransfer. This ability to limit and/or substantially remove suchdeficiencies allows for the systems of the instant application toprovide higher power wireless power transfer in high frequency wirelesspower transmission systems.

For further exemplary illustration, FIG. 8 illustrates a plot for a falland rise of an OOK in-band signal. The fall time (ti) is shown as thetime between when the signal is at 90% voltage (V₄) of the intended fullvoltage (V₁) and falls to about 5% voltage (V₂) of V₁. The rise time(t₃) is shown as the time between when the signal ends being at V₂ andrises to about V₄. Such rise and fall times may be read by a receivingantenna of the signal, and an applicable data communications protocolmay include limits on rise and fall times, such that data isnon-compliant and/or illegible by a receiver if rise and/or fall timesexceed certain bounds.

Returning now to FIGS. 6 and 7 , to achieve limitation and/orsubstantial removal of the mentioned deficiencies, the amplifier 42includes a damping circuit 60. The damping circuit 60 is configured fordamping the AC wireless signal during transmission of the AC wirelesssignal and associated data signals. The damping circuit 60 may beconfigured to reduce rise and fall times during OOK signal transmission,such that the rate of the data signals may not only be compliant and/orlegible, but may also achieve faster data rates and/or enhanced dataranges, when compared to legacy systems. For damping the AC wirelesspower signal, the damping circuit includes, at least, a dampingtransistor 63, which is configured for receiving a damping signal(V_(damp)) from the transmission controller 62. The damping signal isconfigured for switching the damping transistor (on/off) to controldamping of the AC wireless signal during the transmission and/or receiptof wireless data signals. Such transmission of the AC wireless signalsmay be performed by the transmission controller 28 and/or suchtransmission may be via transmission from the wireless receiver system30, within the coupled magnetic field between the antennas 21, 31.

In examples wherein the data signals are conveyed via OOK, the dampingsignal may be substantially opposite and/or an inverse to the state ofthe data signals. This means that if the OOK data signals are in an “on”state, the damping signals instruct the damping transistor to turn “off”and thus the signal is not dissipated via the damping circuit 60 becausethe damping circuit is not set to ground and, thus, a short from theamplifier circuit and the current substantially bypasses the dampingcircuit 60. If the OOK data signals are in an “off” state, then thedamping signals may be “on” and, thus, the damping transistor 63 is setto an “on” state and the current flowing of V_(AC) is damped by thedamping circuit. Thus, when “on,” the damping circuit 60 may beconfigured to dissipate just enough power, current, and/or voltage, suchthat efficiency in the system is not substantially affected and suchdissipation decreases rise and/or fall times in the OOK signal. Further,because the damping signal may instruct the damping transistor 63 toturn “off” when the OOK signal is “on,” then it will not unnecessarilydamp the signal, thus mitigating any efficiency losses from V_(AC), whendamping is not needed.

As illustrated in FIG. 7 , the branch of the amplifier 42 which mayinclude the damping circuit 60, is positioned at the output drain of theamplifier transistor 48. While it is not necessary that the dampingcircuit 60 be positioned here, in some examples, this may aid inproperly damping the output AC wireless signal, as it will be able todamp at the node closest to the amplifier transistor 48 output drain,which is the first node in the circuit wherein energy dissipation isdesired. In such examples, the damping circuit is in electrical parallelconnection with a drain of the amplifier transistor 48. However, it iscertainly possible that the damping circuit be connected proximate tothe antenna 21, proximate to the transmission tuning system 24, and/orproximate to a filter circuit 24.

While the damping circuit 60 is capable of functioning to properly dampthe AC wireless signal for proper communications at higher power highfrequency wireless power transmission, in some examples, the dampingcircuit may include additional components. For instance, as illustrated,the damping circuit 60 may include one or more of a damping diodeD_(DAMP), a damping resistor R_(DAMP), a damping capacitor C_(DAMP),and/or any combinations thereof. R_(DAMP) may be in electrical serieswith the damping transistor 63 and the value of R_(DAMP) (ohms) may beconfigured such that it dissipates at least some power from the powersignal, which may serve to accelerate rise and fall times in anamplitude shift keying signal, an OOK signal, and/or combinationsthereof. In some examples, the value of R_(DAMP) is selected,configured, and/or designed such that R_(DAMP) dissipates the minimumamount of power to achieve the fastest rise and/or fall times in anin-band signal allowable and/or satisfy standards limitations forminimum rise and/or fall times; thereby achieving data fidelity atmaximum efficiency (less power lost to R_(DAMP)) as well as maintainingdata fidelity when the system is unloaded and/or under lightest loadconditions.

C_(DAMP) may also be in series connection with one or both of thedamping transistor 63 and R_(DAMP). C_(DAMP) may be configured to smoothout transition points in an in-band signal and limit overshoot and/orundershoot conditions in such a signal. Further, in some examples,C_(DAMP) may be configured for ensuring the damping performed is 180degrees out of phase with the AC wireless power signal, when thetransistor is activated via the damping signal.

D_(DAMP) may further be included in series with one or more of thedamping transistor 63, R_(DAMP), C_(DAMP), and/or any combinationsthereof. D_(DAMP) is positioned, as shown, such that a current cannotflow out of the damping circuit 60, when the damping transistor 63 is inan off state. The inclusion of D_(DAMP) may prevent power efficiencyloss in the AC power signal when the damping circuit is not active or“on.” Indeed, while the damping transistor 63 is designed such that, inan ideal scenario, it serves to effectively short the damping circuitwhen in an “off” state, in practical terms, some current may still reachthe damping circuit and/or some current may possibly flow in theopposite direction out of the damping circuit 60. Thus, inclusion ofD_(DAMP) may prevent such scenarios and only allow current, power,and/or voltage to be dissipated towards the damping transistor 63. Thisconfiguration, including D_(DAMP), may be desirable when the dampingcircuit 60 is connected at the drain node of the amplifier transistor48, as the signal may be a half-wave sine wave voltage and, thus, thevoltage of V_(AC) is always positive.

Beyond the damping circuit 60, the amplifier 42, in some examples, mayinclude a shunt capacitor C_(SHUNT). C_(SHUNT) may be configured toshunt the AC power signal to ground and charge voltage of the AC powersignal. Thus, C_(SHUNT) may be configured to maintain an efficient andstable waveform for the AC power signal, such that a duty cycle of about50% is maintained and/or such that the shape of the AC power signal issubstantially sinusoidal at positive voltages.

In some examples, the amplifier 42 may include a filter circuit 65. Thefilter circuit 65 may be designed to mitigate and/or filter outelectromagnetic interference (EMI) within the wireless transmissionsystem 20. Design of the filter circuit 65 may be performed in view ofimpedance transfer and/or effects on the impedance transfer of thewireless power transmission 20 due to alterations in tuning made by thetransmission tuning system 24. To that end, the filter circuit 65 may beor include one or more of a low pass filter, a high pass filter, and/ora band pass filter, among other filter circuits that are configured for,at least, mitigating EMI in a wireless power transmission system.

As illustrated, the filter circuit 65 may include a filter inductorL_(o) and a filter capacitor C_(o). The filter circuit 65 may have acomplex impedance and, thus, a resistance through the filter circuit 65may be defined as R_(o). In some such examples, the filter circuit 65may be designed and/or configured for optimization based on, at least, afilter quality factor γ_(FILTER), defined as:

$y_{FILTER} = \frac{1}{R_{o}}\sqrt{\frac{L_{o}}{C_{o}}}.$

In a filter circuit 65 wherein it includes or is embodied by a low passfilter, the cut-off frequency ω_(o)) of the low pass filter is definedas:

$\omega_{o} = \frac{1}{\sqrt{L_{o}C_{o}}}.$

In some wireless power transmission systems 20, it is desired that thecutoff frequency be about 1.03-1.4 times greater than the operatingfrequency of the antenna. Experimental results have determined that, ingeneral, a larger γ_(FILTER) may be preferred, because the largerγ_(FILTER) can improve voltage gain and improve system voltage rippleand timing. Thus, the above values for L_(o) and C_(o) may be set suchthat γ_(FILTER) can be optimized to its highest, ideal level (e.g., whenthe system 10 impedance is conjugately matched for maximum powertransfer), given cutoff frequency restraints and available componentsfor the values of L_(o) and C_(o).

As illustrated in FIG. 7 , the conditioned signal(s) from the amplifier42 is then received by the transmission tuning system 24, prior totransmission by the antenna 21. The transmission tuning system 24 mayinclude tuning and/or impedance matching, filters (e.g. a low passfilter, a high pass filter, a “pi” or “II” filter, a “T” filter, an “L”filter, a “LL” filter, and/or an L-C trap filter, among other filters),network matching, sensing, and/or conditioning elements configured tooptimize wireless transfer of signals from the wireless transmissionsystem 20 to the wireless receiver system 30. Further, the transmissiontuning system 24 may include an impedance matching circuit, which isdesigned to match impedance with a corresponding wireless receiversystem 30 for given power, current, and/or voltage requirements forwireless transmission of one or more of electrical energy, electricalpower, electromagnetic energy, and electronic data. The illustratedtransmission tuning system 24 includes, at least, C_(Z1), C_(Z2). and(operatively associated with the antenna 21) values, all of which may beconfigured for impedance matching in one or both of the wirelesstransmission system 20 and the broader system 10. It is noted thatC_(Tx) refers to the intrinsic capacitance of the antenna 21.

Turning now to FIG. 9 and with continued reference to, at least, FIGS. 1and 2 , the wireless receiver system 30 is illustrated in furtherdetail. The wireless receiver system 30 is configured to receive, atleast, electrical energy, electrical power, electromagnetic energy,and/or electrically transmittable data via near field magnetic couplingfrom the wireless transmission system 20, via the transmission antenna21. As illustrated in FIG. 9 , the wireless receiver system 30 includes,at least, the receiver antenna 31, a receiver tuning and filteringsystem 34, a power conditioning system 32, a receiver control system 36,and a voltage isolation circuit 70. The receiver tuning and filteringsystem 34 may be configured to substantially match the electricalimpedance of the wireless transmission system 20. In some examples, thereceiver tuning and filtering system 34 may be configured to dynamicallyadjust and substantially match the electrical impedance of the receiverantenna 31 to a characteristic impedance of the power generator or theload at a driving frequency of the transmission antenna 20.

As illustrated, the power conditioning system 32 includes a rectifier 33and a voltage regulator 35. In some examples, the rectifier 33 is inelectrical connection with the receiver tuning and filtering system 34.The rectifier 33 is configured to modify the received electrical energyfrom an alternating current electrical energy signal to a direct currentelectrical energy signal. In some examples, the rectifier 33 iscomprised of at least one diode. Some non-limiting exampleconfigurations for the rectifier 33 include, but are not limited toincluding, a full wave rectifier, including a center tapped full waverectifier and a full wave rectifier with filter, a half wave rectifier,including a half wave rectifier with filter, a bridge rectifier,including a bridge rectifier with filter, a split supply rectifier, asingle phase rectifier, a three phase rectifier, a voltage doubler, asynchronous voltage rectifier, a controlled rectifier, an uncontrolledrectifier, and a half controlled rectifier. As electronic devices may besensitive to voltage, additional protection of the electronic device maybe provided by clipper circuits or devices. In this respect, therectifier 33 may further include a clipper circuit or a clipper device,which is a circuit or device that removes either the positive half (tophalf), the negative half (bottom half), or both the positive and thenegative halves of an input AC signal. In other words, a clipper is acircuit or device that limits the positive amplitude, the negativeamplitude, or both the positive and the negative amplitudes of the inputAC signal.

Some non-limiting examples of a voltage regulator 35 include, but arenot limited to, including a series linear voltage regulator, a buckconvertor, a low dropout (LDO) regulator, a shunt linear voltageregulator, a step up switching voltage regulator, a step down switchingvoltage regulator, an invertor voltage regulator, a Zener controlledtransistor series voltage regulator, a charge pump regulator, and anemitter follower voltage regulator. The voltage regulator 35 may furtherinclude a voltage multiplier, which is as an electronic circuit ordevice that delivers an output voltage having an amplitude (peak value)that is two, three, or more times greater than the amplitude (peakvalue) of the input voltage. The voltage regulator 35 is in electricalconnection with the rectifier 33 and configured to adjust the amplitudeof the electrical voltage of the wirelessly received electrical energysignal, after conversion to AC by the rectifier 33. In some examples,the voltage regulator 35 may an LDO linear voltage regulator; however,other voltage regulation circuits and/or systems are contemplated. Asillustrated, the direct current electrical energy signal output by thevoltage regulator 35 is received at the load 16 of the electronic device14. In some examples, a portion of the direct current electrical powersignal may be utilized to power the receiver control system 36 and anycomponents thereof; however, it is certainly possible that the receivercontrol system 36, and any components thereof, may be powered and/orreceive signals from the load 16 (e.g., when the load 16 is a batteryand/or other power source) and/or other components of the electronicdevice 14.

The receiver control system 36 may include, but is not limited toincluding, a receiver controller 38, a communications system 39 and amemory 37. The receiver controller 38 may be any electronic controlleror computing system that includes, at least, a processor which performsoperations, executes control algorithms, stores data, retrieves data,gathers data, controls and/or provides communication with othercomponents and/or subsystems associated with the wireless receiversystem 30. The receiver controller 38 may be a single controller or mayinclude more than one controller disposed to control various functionsand/or features of the wireless receiver system 30. Functionality of thereceiver controller 38 may be implemented in hardware and/or softwareand may rely on one or more data maps relating to the operation of thewireless receiver system 30. To that end, the receiver controller 38 maybe operatively associated with the memory 37. The memory may include oneor both of internal memory, external memory, and/or remote memory (e.g.,a database and/or server operatively connected to the receivercontroller 38 via a network, such as, but not limited to, the Internet).The internal memory and/or external memory may include, but are notlimited to including, one or more of a read only memory (ROM), includingprogrammable read-only memory (PROM), erasable programmable read-onlymemory (EPROM or sometimes but rarely labelled EROM), electricallyerasable programmable read-only memory (EEPROM), random access memory(RAM), including dynamic RAM (DRAM), static RAM (SRAM), synchronousdynamic RAM (SDRAM), single data rate synchronous dynamic RAM (SDRSDRAM), double data rate synchronous dynamic RAM (DDR SDRAM, DDR2, DDR3,DDR4), and graphics double data rate synchronous dynamic RAM (GDDRSDRAM, GDDR2, GDDR3, GDDR4, GDDR5, a flash memory, a portable memory,and the like. Such memory media are examples of nontransitory computerreadable memory media.

Further, while particular elements of the receiver control system 36 areillustrated as subcomponents and/or circuits (e.g., the memory 37, thecommunications system 39, among other contemplated elements) of thereceiver control system 36, such components may be external of thereceiver controller 38. In some examples, the receiver controller 38 maybe and/or include one or more integrated circuits configured to includefunctional elements of one or both of the receiver controller 38 and thewireless receiver system 30, generally. As used herein, the term“integrated circuits” generally refers to a circuit in which all or someof the circuit elements are inseparably associated and electricallyinterconnected so that it is considered to be indivisible for thepurposes of construction and commerce. Such integrated circuits mayinclude, but are not limited to including, thin-film transistors,thick-film technologies, and/or hybrid integrated circuits.

In some examples, the receiver controller 38 may be a dedicated circuitconfigured to send and receive data at a given operating frequency. Forexample, the receiver controller 38 may be a tagging or identifierintegrated circuit, such as, but not limited to, an NFC tag and/orlabelling integrated circuit. Examples of such NFC tags and/or labellingintegrated circuits include the NTAG® family of integrated circuitsmanufactured by NXP Semiconductors N.V. However, the communicationssystem 39 is certainly not limited to these example components and, insome examples, the communications system 39 may be implemented withanother integrated circuit (e.g., integrated with the receivercontroller 38), and/or may be another transceiver of or operativelyassociated with one or both of the electronic device 14 and the wirelessreceiver system 30, among other contemplated communication systemsand/or apparatus. Further, in some examples, functions of thecommunications system 39 may be integrated with the receiver controller38, such that the controller modifies the inductive field between theantennas 21, 31 to communicate in the frequency band of wireless powertransfer operating frequency.

Turning now to FIGS. 10 and 11 , the wireless receiver system 30 isillustrated in further detail to show some example functionality of oneor more of the receiver controller 38, the voltage isolation circuit 70,and the rectifier 33. The block diagram of the wireless receiver system30 illustrates one or more electrical signals and the conditioning ofsuch signals, altering of such signals, transforming of such signals,rectifying of such signals, amplification of such signals, andcombinations thereof. Similarly to FIG. 6 , DC power signals areillustrated with heavily bolded lines, such that the lines aresignificantly thicker than other solid lines in FIG. 6 and other figuresof the instant application, AC signals are illustrated as substantiallysinusoidal wave forms with a thickness significantly less bolded thanthat of the DC power signal bolding, and data signals are represented asdotted lines. FIG. 11 illustrates sample electrical components forelements of the wireless transmission system, and subcomponents thereof,in a simplified form. Note that FIG. 11 may represent one branch orsubsection of a schematic for the wireless receiver system 30 and/orcomponents of the wireless receiver system 30 may be omitted from theschematic, illustrated in FIG. 11 , for clarity.

As illustrated in FIG. 10 , the receiver antenna 31 receives the ACwireless signal, which includes the AC power signal (V_(AC)) and thedata signals (denoted as “Data” in FIG. 10 ), from the transmitterantenna 21 of the wireless transmission system 20. (It should beunderstood an example of a transmitted AC power signal and data signalwas previously shown in FIG. 6 ). V_(AC) will be received at therectifier 33 and/or the broader receiver power conditioning system 32,wherein the AC wireless power signal is converted to a DC wireless powersignal (V_(DC_REKT)). V_(DC­_REKT) is then provided to, at least, theload 16 that is operatively associated with the wireless receiver system30. In some examples, V_(DC_REKT) is regulated by the voltage regulator35 and provided as a DC input voltage (V_(DC_CONT)) for the receivercontroller 38. In some examples, such as the signal path shown in FIG.11 , the receiver controller 38 may be directly powered by the load 16.In some other examples, the receiver controller 38 need not be poweredby the load 16 and/or receipt of V_(DC_CONT), but the receivercontroller 38 may harness, capture, and/or store power from V_(AC), aspower receipt occurring in receiving, decoding, and/or otherwisedetecting the data signals in-band of V_(AC).

The receiver controller 38 is configured to perform one or more ofencoding the wireless data signals, decoding the wireless data signals,receiving the wireless data signals, transmitting the wireless datasignals, and/or any combinations thereof. In examples, wherein the datasignals are encoded and/or decoded as amplitude shift keyed (ASK)signals and/or OOK signals, the receiver controller 38 may receiveand/or otherwise detect or monitor voltage levels of V_(AC) to detectin-band ASK and/or OOK signals. However, at higher power levels thanthose currently utilized in standard high frequency, NFMC communicationsand/or low power wireless power transmission, large voltages and/orlarge voltage swings at the input of a controller, such as thecontroller 38, may be too large for legacy microprocessor controllers tohandle without disfunction or damage being done to suchmicrocontrollers. Additionally, certain microcontrollers may only beoperable at certain operating voltage ranges and, thus, when highfrequency wireless power transfer occurs, the voltage swings at theinput to such microcontrollers may be out of range or too wide of arange for consistent operation of the microcontroller.

For example, in some high frequency higher power wireless power transfersystems 10, when an output power from the wireless power transmitter 20is greater than 1 W, voltage across the controller 38 may be higher thandesired for the controller 38. Higher voltage, lower currentconfigurations are often desirable, as such configurations may generatelower thermal losses and/or lower generated heat in the system 10, incomparison to a high current, low voltage transmission. To that end, theload 16 may not be a consistent load, meaning that the resistance and/orimpedance at the load 16 may swing drastically during, before, and/orafter an instance of wireless power transfer.

This is particularly an issue when the load 16 is a battery or otherpower storing device, as a fully charged battery has a much higherresistance than a fully depleted battery. For the purposes of thisillustrative discussion, we will assume:

wherein R_(LOAD) _(_MIN) is the minimum resistance of the load 16 (e.g.,if the load 16 is or includes a battery, when the battery of the load 16is depleted), I_(AC) _(_MIN) is the current at R_(LOAD) _(_MIN), V_(AC)_(_MIN) is the voltage of V_(AC) when the load 16 is at its minimumresistance and P_(AC) _(_MIN) is the optimal power level for the load 16at its minimal resistance. Further, we will assume:

wherein R_(LOAD) _(_MAX) is the maximum resistance of the load 16 (e.g.,if the load 16 is or includes a battery, when the battery of the load 16is depleted), I_(AC_MAX) is the current at V_(AC) _(_MAX), V_(AC)_(_MAX) is the voltage of V_(AC) when the load 16 is at its minimumresistance and P_(AC) _(_MAX) is the optimal power level for the load 16at its maximal resistance.

Accordingly, as the current is desired to stay relatively low, theinverse relationship between I_(AC) and V_(AC) dictate that the voltagerange must naturally shift, in higher ranges, with the change ofresistance at the load 16. However, such voltage shifts may beunacceptable for proper function of the controller 38. To mitigate theseissues, the voltage isolation circuit 70 is included to isolate therange of voltages that can be seen at a data input and/or output of thecontroller 38 to an isolated controller voltage (V_(CONT)), which is ascaled version of V_(AC) and, thus, comparably scales any voltage-basedin-band data input and/or output at the controller 38. Accordingly, if arange for the AC wireless signal that is an unacceptable input range forthe controller 38 is represented by

then the voltage isolation circuit 70 is configured to isolate thecontroller-unacceptable voltage range from the controller 38, by settingan impedance transformation to minimize the voltage swing and providethe controller with a scaled version of Vac, which does notsubstantially alter the data signal at receipt. Such a scaled controllervoltage, based on V_(AC), is V_(CONT), where

While an altering load is one possible reason that an unacceptablevoltage swing may occur at a data input of a controller, there may beother physical, electrical, and/or mechanical characteristics and/orphenomena that may affect voltage swings in V_(AC), such as, but notlimited to, changes in coupling (k) between the antennas 21, 31,detuning of the system(s) 10, 20, 30 due to foreign objects, proximityof another receiver system 30 within a common field area, among otherthings.

As best illustrated in FIG. 11 , the voltage isolation circuit 70includes at least two capacitors, a first isolation capacitor C_(ISO1)and a second isolation capacitor C_(ISO2). While only two series, splitcapacitors are illustrated in FIG. 11 , it should also be understoodthat the voltage isolation circuit may include additional pairs of splitseries capacitors. C_(ISO1) and C_(ISO2) are electrically in series withone another, with a node therebetween, the node providing a connectionto the data input of the receiver controller 38. C_(ISO1) and C_(ISO2)are configured to regulate V_(AC) to generate the acceptable voltageinput range V_(CONT) for input to the controller. Thus, the voltageisolation circuit 70 is configured to isolate the controller 38 fromV_(AC), which is a load voltage, if one considers the rectifier 33 to bepart of a downstream load from the receiver controller 38.

In some examples, the capacitance values are configured such that aparallel combination of all capacitors of the voltage isolation circuit70 (e.g. C_(ISO1) and C_(ISO2)) is equal to a total capacitance for thevoltage isolation circuit (C_(TOTAL)). Thus,

wherein C_(TOTAL) is a constant capacitance configured for theacceptable voltage input range for input to the controller. C_(TOTAL)can be determined by experimentation and/or can be configured viamathematical derivation for a particular microcontroller embodying thereceiver controller 38.

In some examples, with a constant C_(TOTAL), individual values for theisolation capacitors C_(ISO1) and C_(ISO2) may be configured inaccordance with the following relationships:

wherein t_(v) is a scaling factor, which can be experimentally alteredto determine the best scaling values for C_(ISO1) and C_(ISO2), for agiven system. Alternatively, t_(v) may be mathematically derived, basedon desired electrical conditions for the system. In some examples (whichmay be derived from experimental results), t_(v) may be in a range ofabout 3 to about 10.

FIG. 11 further illustrates an example for the receiver tuning andfiltering system 34, which may be configured for utilization inconjunction with the voltage isolation circuit 70. The receiver tuningand filtering system 34 of FIG. 11 includes a controller capacitorC_(CONT), which is connected in series with the data input of thereceiver controller 38. The controller capacitor is configured forfurther scaling of V_(AC) at the controller, as altered by the voltageisolation circuit 70. To that end, the first and second isolationcapacitors, as shown, may be connected in electrical parallel, withrespect to the controller capacitor.

Additionally, in some examples, the receiver tuning and filtering system34 includes a receiver shunt capacitor C_(RxSHUNT), which is connectedin electrical parallel with the receiver antenna 31. C_(RxSHUNT) isutilized for initial tuning of the impedance of the wireless receiversystem 30 and/or the broader system 30 for proper impedance matchingand/or C_(RxSHUNT) is included to increase the voltage gain of a signalreceived by the receiver antenna 31.

The wireless receiver system 30, utilizing the voltage isolation circuit70, may have the capability to achieve proper data communicationsfidelity at greater receipt power levels at the load 16, when comparedto other high frequency wireless power transmission systems. To thatend, the wireless receiver system 30, with the voltage isolation circuit70, is capable of receiving power from the wireless transmission systemthat has an output power at levels over 1 W of power, whereas legacyhigh frequency systems may be limited to receipt from output levels ofonly less than 1 W of power. For example, in legacy NFC-DC systems, thepoller (receiver system) often utilizes a microprocessor from the NTAGfamily of microprocessors, which was initially designed for very lowpower data communications. NTAG microprocessors, without protection orisolation, may not adequately and/or efficiently receive wireless powersignals at output levels over 1 W. However, inventors of the presentapplication have found, in experimental results, that when utilizingvoltage isolation circuits as disclosed herein, the NTAG chip may beutilized and/or retrofitted for wireless power transfer and wirelesscommunications, either independently or simultaneously.

To that end, the voltage isolation circuits disclosed herein may utilizeinexpensive components (e.g., isolation capacitors) to modifyfunctionality of legacy, inexpensive microprocessors (e.g., an NTAGfamily microprocessor), for new uses and/or improved functionality.Further, while alternative controllers may be used as the receivercontroller 38 that may be more capable of receipt at higher voltagelevels and/or voltage swings, such controllers may be cost prohibitive,in comparison to legacy controllers. Accordingly, the systems andmethods herein allow for use of less costly components, for high powerhigh frequency wireless power transfer.

FIG. 12 illustrates an example, non-limiting embodiment of one or moreof the transmission antenna 21 and the receiver antenna 31 that may beused with any of the systems, methods, and/or apparatus disclosedherein. In the illustrated embodiment, the antenna 21, 31, is a flatspiral coil configuration. Non-limiting examples can be found in U.S.Pat. Nos. 9,941,743, 9,960,628, 9,941,743 all to Peralta et al.;9,948,129, 10,063,100 to Singh et al.; 9,941590 to Luzinski; 9,960,629to Rajagopalan et al.; and U.S. Pat. App. Nos. 2017/0040107,2017/0040105, 2017/0040688 to Peralta et al.; all of which are assignedto the assignee of the present application and incorporated fully hereinby reference.

In addition, the antenna 21, 31may be constructed having amulti-layer-multi-turn (MLMT) construction in which at least oneinsulator is positioned between a plurality of conductors. Non-limitingexamples of antennas having an MLMT construction that may beincorporated within the wireless transmission system(s) 20 and/or thewireless receiver system(s) 30 may be found in U.S. Pat. Nos. 8,610,530,8,653,927, 8,680,960, 8,692,641, 8,692,642, 8,698,590, 8,698,591,8,707,546, 8,710,948, 8,803,649, 8,823,481, 8,823,482, 8,855,786,8,898,885, 9,208,942, 9,232,893, and 9,300,046 to Singh et al., all ofwhich are assigned to the assignee of the present application areincorporated fully herein. These are merely exemplary antenna examples;however, it is contemplated that the antennas 21, 31 may be any antennacapable of the aforementioned higher power, high frequency wirelesspower transfer.

FIG. 13 is a side view of an example listening device system 400A whichmay operatively associated with the wireless transmission system 20 orother wireless power transmission system on a mobile device such as amobile phone. The listening device system 400A includes one or morelistening devices 430A. As used herein, a “listening device” may includeany portable device designed to output sound that can be heard by auser, such as headphones, earbuds, canalphones, over ear headphones,ear-fitting headphones, headsets, digital conferencing headsets, amongother listening devices. Headphones are one type of portable listeningdevice, while portable speakers are another.

The term “headphones” represents a pair of small, portable listeningdevices that are designed to be worn on or around a user’s head. Suchdevices convert an electrical signal to a corresponding sound that canbe heard by the user of the device. Headphones include traditionalheadphones that are worn over a user’s head and include left and rightlistening devices connected to each other by a head band, headsets, andearbuds. Earbuds may be defined as small headphones that are designed tobe fitted directly in a user’s ear. As used herein, the term “earbuds,”which can also be referred to as ear-phones or ear-fitting headphones,includes both small headphones that fit within a user’s outer ear facingthe ear canal without being inserted in the ear canal, and in-earheadphones, sometimes referred to as canalphones, that are inserted inthe ear canal itself.

The wireless receiver system 30 may be integrated with the listeningdevice(s) 430A and may be utilized to charge a battery or other storagedevice of or associated with the listening device(s) 430A and/or may beused to directly power one or more components of or associated with thelistening device(s) 430A.

As illustrated, the listening device system 400A includes a case 420,which will be described in greater detail below. The case 420, is acontainer in which the listening device(s) 430A may reside in locations402 (“hollows”) in an orientation and position that facilitates resonantcoupling with an adjacent power transmission system such as system 20,in a mobile electronic device such as a mobile phone or wearable device.

The locations 402 may be mechanically defined, e.g., via sockets, slotsor similar features, configured for aligning the wireless transmissionsystem 20 with the wireless mobile device (not shown in FIG. 13 ) forproper placement for wireless power transfer. The listening devices 430Amay be retained in their locations 402 via gravity, friction, magneticforce, clips, clamps, closures or other suitable mechanisms orarrangements.

FIG. 14 is a simplified back view of a mobile phone 80, whereon the case420 has been mounted. In particular, as will be seen, the case 420 ismounted in a location and orientation such that the listening devices430A are in a position to be charged by a wireless power transferantenna such as an antenna 21.

Referring now to FIG. 15 in order to further expand on the relationshipbetween the mobile phone 80 and the listening devices 430A when they arein the mounted case 420, the power transfer antenna 81 (21) of themobile phone 80 is located low on the back side of the mobile phone 80adjacent the rear surface 83.

Each listening device 430A includes a wireless power receiving antenna85 (31) positioned to exchange power and data with the power transferantenna 81 (21) of the mobile phone 80. The wireless power receivingantenna 85 (31) of each listening device 430A is linked to a wirelesspower receiving system such as wireless receiver system 30 of FIG. 1 .(not shown in FIG. 15 ). When the case 420 is affixed to the mobilephone 80 and the listening devices 430A are placed in their locations402 within the case, the wireless power receiving antennas 85 (31) ofthe listening devices 430A overlap the power transfer antenna 81 (21) ofthe mobile phone 80 at an orientation (e.g., parallel planar) anddistance (e.g., distance 17 of FIG. 1 ), the antenna 81 is able toresonantly couple with the antennas 85. In this way, the mobile phone 80charges the listening devices 430A so that they can be removed from thecase and again employed by a user for listening.

While the locations 402 should be accurately placed to allow resonantcoupling when the listening devices 430A are in the mounted case 420,the form and shape of the case 420 is not otherwise restricted.Moreover, depending upon the attachment mechanism used to mount the case420 to the mobile phone 80, varying attachment structures may be presenton or in the case 420. That said, an example form of the case 420 isshown in FIG. 16 . In the illustrated example, the case 420 is of anessentially rectangular cube form, with its depth dimension 91, widthdimension 93 and height dimension 95 being sufficient to accommodate theproperly-oriented listening devices 430A.

As noted above, the mounting of the case 420 may be temporary, such asvia a slide, clip, hook and loop fastener, etc., or may be permanent,such as via double-sided tape, epoxy, mechanical fastener, and so on.The positional arrangement between the case 420 and the mobile phone 80will be described in greater detail below. In keeping with the FIG. 13 ,the case 420 as illustrated in FIG. 14 includes locations 402 in whichthe listening devices 430A may reside in an orientation and positionthat facilitate resonant coupling with the power transmission system ofthe mobile phone 80.

The case 420 as illustrated in FIG. 16 may act as a case for thelistening devices 430A while not attached to the mobile phone 80 aswell, since in encloses the listening devices 430A on both front andback. However, it will be appreciated that the use of the case 420 forcharging does not require enclosure in front of and behind theenclosures 402, if the case 420 only contains the listening devices 430Awhen it is mounted on the back of the mobile phone.

With this in mind, FIG. 17 shows an alternative embodiment of the case421, wherein the dimensions of the case 421 are dictated by the sameconsiderations, both aesthetic and functional, but the alternative case421 does not constrain the listening devices 430A on the side facing themobile phone 80 when mounted. Similarly, other aspect of the case 420may be minimized or eliminated without altering its primary functions.For example, the locations 402, as illustrated, are such that a bottomenclosure is not needed. That is, the shape of the listening devices430A forms an interference fit in the case 420, preventing the listeningdevices 430A from falling further downward.

Although the embodiments illustrated thus far do not exhibit attachmentfeatures, and may be attached via any surface mount technology,transient or permanent, other embodiments may exhibit externalattachment features. For example, the case 423 illustrated in FIG. 18slides onto the mobile phone 80 and is retained thereon, e.g., via afriction fit of the phone 80 within the lips 97. Alternatively, the case423 may be retained via a detent and mating ridge or bump, or by othermechanical retention means rather than friction.

In embodiments such as shown in FIG. 17 , wherein flexibity is used toallow a portion of the case 420, 421, 423 to accommodate a detent,ridge, friction fit or other tension-assisted attachment mode ormechanism, the case 420, 421, 423 may comprise a flexible or semi-rigidresilient material such as metal sheet or strip, polymer, rubber orother flexible or semi-rigid resilient material.

A placement aid may be included as part of the case to allow accuratemounting of the case to the mobile device. In the embodiment illustratedin FIG. 19 , the placement aid comprises a bottom ledge 425 that engagesthe bottom edge of the mobile phone 80 when the case 427 is slid up ontothe mobile device 80 or otherwise affixed to the mobile device 80. Thisensures accurate placement of any listening device 430 in the case 425relative to the power transfer antenna 81 of the mobile device 80, sothat wireless coupling may be efficiently executed.

The systems, methods, and apparatus disclosed herein are designed tooperate in an efficient, stable and reliable manner to satisfy a varietyof operating and environmental conditions. The systems, methods, and/orapparatus disclosed herein are designed to operate in a wide range ofthermal and mechanical stress environments so that data and/orelectrical energy is transmitted efficiently and with minimal loss. Inaddition, the system 10 may be designed with a small form factor using afabrication technology that allows for scalability, and at a cost thatis amenable to developers and adopters. In addition, the systems,methods, and apparatus disclosed herein may be designed to operate overa wide range of frequencies to meet the requirements of a wide range ofapplications.

In an embodiment, a ferrite shield may be incorporated within theantenna structure to improve antenna performance. Selection of theferrite shield material may be dependent on the operating frequency asthe complex magnetic permeability (µ=µ′-j*µ″) is frequency dependent.The material may be a polymer, a sintered flexible ferrite sheet, arigid shield, or a hybrid shield, wherein the hybrid shield comprises arigid portion and a flexible portion. Additionally, the magnetic shieldmay be composed of varying material compositions. Examples of materialsmay include, but are not limited to, zinc comprising ferrite materialssuch as manganese-zinc, nickel-zinc, copper-zinc, magnesium-zinc, andcombinations thereof.

As used herein, the phrase “at least one of” preceding a series ofitems, with the term “and” or “or” to separate any of the items,modifies the list as a whole, rather than each member of the list (i.e.,each item). The phrase “at least one of” does not require selection ofat least one of each item listed; rather, the phrase allows a meaningthat includes at least one of any one of the items, and/or at least oneof any combination of the items, and/or at least one of each of theitems. By way of example, the phrases “at least one of A, B, and C” or“at least one of A, B, or C” each refer to only A, only B, or only C;any combination of A, B, and C; and/or at least one of each of A, B, andC.

The predicate words “configured to”, “operable to”, and “programmed to”do not imply any particular tangible or intangible modification of asubject, but, rather, are intended to be used interchangeably. In one ormore embodiments, a processor configured to monitor and control anoperation or a component may also mean the processor being programmed tomonitor and control the operation or the processor being operable tomonitor and control the operation. Likewise, a processor configured toexecute code can be construed as a processor programmed to execute codeor operable to execute code.

A phrase such as “an aspect” does not imply that such aspect isessential to the subject technology or that such aspect applies to allconfigurations of the subject technology. A disclosure relating to anaspect may apply to all configurations, or one or more configurations.An aspect may provide one or more examples of the disclosure. A phrasesuch as an “aspect” may refer to one or more aspects and vice versa. Aphrase such as an “embodiment” does not imply that such embodiment isessential to the subject technology or that such embodiment applies toall configurations of the subject technology. A disclosure relating toan embodiment may apply to all embodiments, or one or more embodiments.An embodiment may provide one or more examples of the disclosure. Aphrase such an “embodiment” may refer to one or more embodiments andvice versa. A phrase such as a “configuration” does not imply that suchconfiguration is essential to the subject technology or that suchconfiguration applies to all configurations of the subject technology. Adisclosure relating to a configuration may apply to all configurations,or one or more configurations. A configuration may provide one or moreexamples of the disclosure. A phrase such as a “configuration” may referto one or more configurations and vice versa.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any embodiment described herein as“exemplary” or as an “example” is not necessarily to be construed aspreferred or advantageous over other embodiments. Furthermore, to theextent that the term “include,” “have,” or the like is used in thedescription or the claims, such term is intended to be inclusive in amanner similar to the term “comprise” as “comprise” is interpreted whenemployed as a transitional word in a claim. Furthermore, to the extentthat the term “include,” “have,” or the like is used in the descriptionor the claims, such term is intended to be inclusive in a manner similarto the term “comprise” as “comprise” is interpreted when employed as atransitional word in a claim.

All structural and functional equivalents to the elements of the variousaspects described throughout this disclosure that are known or latercome to be known to those of ordinary skill in the art are expresslyincorporated herein by reference and are intended to be encompassed bythe claims. Moreover, nothing disclosed herein is intended to bededicated to the public regardless of whether such disclosure isexplicitly recited in the claims. No claim element is to be construedunder the provisions of 35 U.S.C. § 112, sixth paragraph, unless theelement is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor.”

Reference to an element in the singular is not intended to mean “one andonly one” unless specifically so stated, but rather “one or more.”Unless specifically stated otherwise, the term “some” refers to one ormore. Pronouns in the masculine (e.g., his) include the feminine andneuter gender (e.g., her and its) and vice versa. Headings andsubheadings, if any, are used for convenience only and do not limit thesubject disclosure.

While this specification contains many specifics, these should not beconstrued as limitations on the scope of what may be claimed, but ratheras descriptions of particular implementations of the subject matter.Certain features that are described in this specification in the contextof separate embodiments can also be implemented in combination in asingle embodiment. Conversely, various features that are described inthe context of a single embodiment can also be implemented in multipleembodiments separately or in any suitable sub-combination. Moreover,although features may be described above as acting in certaincombinations and even initially claimed as such, one or more featuresfrom a claimed combination can in some cases be excised from thecombination, and the claimed combination may be directed to a subcombination or variation of a sub combination.

What is claimed is:
 1. A wireless power transfer system for mobilecharging of one or more listening devices comprising: a case configuredfor attachment to a mobile electronic device having a wireless powertransfer antenna, the case comprising: a hollow for each of the one ormore listening devices having a wireless power receiving antennacouplable to a wireless power transfer antenna, each hollow being shapedand located to hold an enclosed listening device in a coupling positionwith the wireless power transfer antenna of the mobile electronic devicewhen the case is mounted to the mobile electronic device; and anattachment for attaching the case to the mobile electronic device. 2.The wireless power transfer system of claim 1, wherein the wirelesspower receiving antenna couples at an operating frequency in a range ofabout 13.553 MHz to about 13.567 MHz.
 3. The wireless power transfersystem of claim 1, wherein an output power of the wireless powertransfer antenna is greater than about 1 Watt.
 4. The wireless powertransfer system of claim 1, wherein the one or more listening devicesinclude two listening devices and the case includes two respectivehollows.
 5. The wireless power transfer system of claim 1, wherein thecase is configured for attachment to a back surface of the mobileelectronic device.
 6. The wireless power transfer system of claim 1,wherein the mobile electronic device is a mobile phone.
 7. The wirelesspower transfer system of claim 1, wherein the mobile electronic deviceis a wearable device.
 8. The wireless power transfer system of claim 1,wherein the attachment comprises at least one of a clip, a bracket, anadhesive and a hook and loop fastener.
 9. A Near-Field CommunicationsDirect Charge (NFC-DC) system for mobile charging of one or morelistening devices comprising: a case configured for attachment to amobile electronic device having an NFC-DC power transfer antenna, thecase comprising: a hollow for each of the one or more listening deviceshaving an NFC-DC receiving antenna couplable to an NFC-DC power transferantenna, each hollow being shaped and located to hold an enclosedlistening device in a coupling position with the NFC-DC power transferantenna of the mobile electronic device when the case is mounted to themobile electronic device; and an attachment for attaching the case tothe mobile electronic device.
 10. The NFC-DC system of claim 9, whereinthe NFC-DC receiving antenna couples at an operating frequency in arange of about 13.553 MHz to about 13.567 MHz.
 11. The NFC-DC system ofclaim 9, wherein an output power of the NFC-DC power transfer antenna isgreater than about 1 Watt.
 12. The NFC-DC system of claim 9, wherein theone or more listening devices include two listening devices and the caseincludes two respective hollows.
 13. The NFC-DC system of claim 9,wherein the case is configured for attachment to a back surface of themobile electronic device.
 14. The NFC-DC system of claim 9, wherein themobile electronic device is a mobile phone.
 15. The NFC-DC system ofclaim 9, wherein the mobile electronic device is a wearable device. 16.The NFC-DC system of claim 9, wherein the attachment comprises at leastone of a clip, a bracket, an adhesive and a hook and loop fastener. 17.A wireless power transfer system comprising: a mobile electronic devicehaving a having a wireless power transfer antenna associated with awireless power transmission system; a case attached to the mobileelectronic device adjacent to the wireless power transfer antenna, thecase comprising a hollow for each of one or more listening deviceshaving a wireless power receiving antenna couplable to the wirelesspower transfer antenna, each hollow being shaped and located to hold anenclosed listening device in a coupling position with the wireless powertransfer antenna of the mobile electronic device.
 18. The wireless powertransfer system of claim 17, wherein the wireless power receivingantenna and wireless power transfer antenna couple at an operatingfrequency in a range of about 13.553 MHz to about 13.567 MHz.
 19. Thewireless power transfer system of claim 17, wherein an output power ofthe wireless power transfer antenna is greater than about 1 Watt. 20.The wireless power transfer system of claim 17, wherein the mobileelectronic device is one of a mobile phone and a wearable device.